RU2262698C1 - Beam structure testing device - Google Patents

Abstract

FIELD: building, particularly testing equipment to perform beam structure testing.

SUBSTANCE: device has base, support posts and loading means. Loading means is adapted for alternating loads application and is provided with reverse mechanism. Reverse mechanism is made as two pairs of vertical pull rods connected one to another by two cross-arms. One pair of vertical pull rods is fixedly connected to the base, another one may be connected to beam structure. Cross-arms are installed one above another and extend in horizontal direction. Discrete load transducer is installed on lower cross-arm. The transducer may be made as hydraulic jack. Each pull rod has adjusting nuts to regulate free cross-arm and pull rod movement and to change direction of load application.

EFFECT: possibility to apply alternating loads to object to be tested.

2 l, 3 dwg

Description

The invention relates to the field of construction, in particular to testing equipment, and can be used to test beam structures.

A device for mechanical testing of concrete products according to the author's certificate of the USSR No. 1689848, class. G 01 N 33/38, 1991, a pallet with end stops and thermal sides, a loading device with movable rods and a measuring device. It is equipped with a middle thermal board, fixed rods and washers having threaded bushings, removable middle stops in the form of box elements with anchors, threaded bushings and couplings, movable rods are equipped with threaded bushings, end stops are made with grooves for rods, the pallet is made with a thermal compartment, while couplings are connected to threaded bushings. The rods are equipped with elements for connection with the studied reinforcement. The device is equipped with a set of removable thermal boards with conical grooves and internal conical overlays.

However, this device has a complex structure and does not allow you to apply alternating loads.

There is a well-known test bench for prefabricated reinforced concrete beams of the Research Institute - 200 N.N.Aistov, Testing of Structures, State Publishing House of Literature on Construction, Architecture and Building Materials. M.-L., 1960, pp. 178-179, fig. 148, adopted by the applicant for the prototype. The stand includes four concrete foundations, vertical guides of two channels, concreted in each foundation. Supporting pillows made of steel sheets are installed on the upper faces of the foundations, and the movable supports of the test beams are located on steel rollers. The loading platform is a beam cage of eight I-beams and is suspended from each test beam at two points using steel clamps having centering devices to ensure central transfer of loads.

This stand is a complex and bulky design, the tests on which are carried out with the application of the load only in one direction.

An object of the invention is the creation of a simple and compact design of the installation for testing beam structures, with the ability to apply alternating loads.

The problem is solved in that in the proposed technical solution, the loading device is configured to apply alternating loads and is equipped with a reverse mechanism, which is made in the form of two pairs of vertical rods that are interconnected by two traverses, one pair of rods is rigidly mounted on the base, and the other is made with the possibility of fixing on the beam structure, the traverses are mounted horizontally one above the other, and a discrete load source is installed on the bottom, each link is equipped with a regulator irovochnymi nuts for adjusting the freewheel traverse and drafts and changes in direction of the load.

In addition, the discrete load source is made in the form of a hydraulic jack.

Figure 1 shows the installation for testing beam structures, General view;

Figure 2 - installation for testing beam structures with a load down;

Figure 3 - installation for testing beam structures with a load up.

The installation for testing beam structures consists of a base 1, rigidly mounted support columns 2, a loading device, which is configured to apply alternating loads and is equipped with a reverse mechanism 3 and a source of discrete load 4. The reverse mechanism 3 is made in the form of two pairs of vertical rods, which are interconnected by two traverses 5 and 6 with holes for these rods. One pair of rods 7 and 8 is rigidly mounted on the base 1, and the other pair of rods 9 and 10 is made with the possibility of fixing on the tested beam structure 11 by means of clamps 12 of the frame structure. In this case, the ends of the beam structure 11 are fixed in the supporting posts 2 by means of the elements 13. Traverses 5 and 6 are mounted horizontally one above the other, and a discrete load source 4, which is made in the form of a hydraulic jack, is installed on the lower traverse 6. Each rod 7 and 8, 9 and 10 is equipped with adjusting nuts: rod 7 - nuts 14, 15, and 16, rod 8 - nuts 17, 18 and 19, rod 9 - nuts 20 and 21, rod 10 - nuts 22 and 23. The adjusting nuts 14-23 are designed to adjust the free travel of the traverse 5, 6 and rods 9 and 10 and change the direction of action of the loads applied to the tested beam structure 11, since the source of discrete load 4 always acts in one direction. In addition, the installation is equipped with a dynamometer 24, fixing the loads applied to the beam structure 11.

Installation for testing beam structures works as follows.

The beam structure 11 is mounted on the supporting posts 2 and secured by the elements 13. The rods 9 and 10 are fastened by means of the clamps 12 to the beam structure 11, thereby connecting a loading device to it. By applying oil under pressure from the pumping station to the discrete load source 4 - a single-acting hydraulic jack, the load is transmitted through the reversing mechanism 3. Depending on the position of the adjusting nuts 14-23 on the rods 7 and 8 and 9 and 10, they change the direction of effort, which makes it possible the beam structure 11 is deformed in the plane of action of the bending moment with the change of the arrow of the deflection.

To create a downward deflection (Figure 2), the nuts 14 and 17 and the nuts 21 and 23 are turned off, releasing the crosshead 6, giving it free movement downward under the action of a discrete load source 4, and the nuts 16 and 19 are pressed against the crosshead 5 and restrict its upward movement . Traverse 6 is hung on nuts 20 and 22, which limit its downward movement. But when the source 4 applies the force, the traverse 6, resting on the nuts 20 and 22, begins to pull down the rods 9 and 10, suspended on the beam structure 11, which load it, creating a certain bending moment acting on the beam structure 11 in the places of installation of the rods 9 and 10. Thus, the beam structure is tested in one direction of application of the bending moment — positive.

To change the sign of the application of the bending moment to the opposite - negative, it is necessary to loosen the nuts 16, 20 and 19, 22 (Figure 3), and tighten the nuts 14, 17 and 21, 23 to the corresponding yokes. Then, when the force is applied by the source of the discrete load 4, the yoke 6 remains in place and is pressed against the nuts 14 and 17, and the yoke 5, having been freed from the nuts 16, 20 and 19, 22 and pressed against the nuts 21 and 23 of the rods 9 and 10, moves up lifts up and rods 9 and 10, which act on the fixed beam structure 11, create a bending moment with the arrow bending upward, while the dynamometer 24 captures the applied force. In this way, the beam structure is tested in the other direction of application of the bending moment.

Using the proposed technical solution allowed us to create a simple and compact installation that allows you to test beam structures without shifting to alternating loads.

Claims (2)

1. Installation for testing beam structures, comprising a base, support legs, a loading device, characterized in that the loading device is made with the possibility of applying alternating loads and is equipped with a reverse mechanism, which is made in the form of two pairs of vertical rods, which are interconnected by two traverses, one pair of rods is rigidly mounted on the base, and the other is made with the possibility of fixing on the beam structure, the traverses are installed horizontally one above the other, and on the bottom n discrete source load, each strut is provided with adjusting nuts to adjust the overrunning traverse and drafts and changes direction of the loads. 2. Installation according to claim 1, characterized in that the discrete load source is made in the form of a hydraulic jack.

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